Carroting reagents and process



Patented Maro lib, 1943 FFECE CARRGTKNG REAGENTS AND PROCESS Albert Frank Bowles, Naugatuck, Conn, and Anthony .l Keegel, Jersey City, N. 5., assignors to Trinity Holding Corporation, Beacon Falls, Conn, a corporation of Connecticut No Drawing. Application February 19, 1947, Serial No. 729,662

8 (Claims. (oi. 8ll2) This application deals with the production of new and superior carrotin reagents for felting animal fur fibers, particularly those of the wild rodents such as rabbits, hares, muskrats, beavers, otters, moles, and the like, and of animals of the sebraculae species, including foxes, weasels, cats, etc, More specifically, it relates to the controlled hydrolysis and breakdown of the cystine-rich protein fibers, heretofore mentioned, so as to produce a superior felt of high quality.

In our co-pending application Serial No. 625,681, filed on October 30, 1945, now abandoned, and in our co-pending application Serial No. 630,139, filed on November 21, 1945, which is a continuation-impart of the earlier application, and of which, this present application is a continuation-impart, it was brought out that animal fur fibers, of the type specified above, are richer in cystine groups in the protein structure than are thefibers of other animals. It is these groups which make it possible for the fur to felt, upon treatment with the proper reagents.

It was also disclosed that, by means of the present process, there first occurs a mild hydrolysis of the amino acid-salt bridge, after which oxidation of the peptid chains takes place, resulting in the reduction of the disulfide group in the cystine portion, to form the xanthoproteic dimercaptan, resulting in a partial depolymerization or cleavage and a softening of the fiber.

According to the present invention, it has been found that a nitric acid solution of radioactive salts, particularly uranium, thorium, together with strontium, the latter metals used in the proportion to give an overall average atomic weight of 195 to 220, preferably about 200. appears to react With the dimercaptan in such a way as to produce felting properties far superior to those obtained with other carroting reagents now employed. The use of certain hydrolyzing acids, buffering salts and retarding agents aids appreciably in enhancing the felting effect. Also the use of a specific oxidizing solution, will be subsequently described, has been found to produce a finished felt of excellent color and considerably higher tensile strength than that produced by existing methods.

In the preferred embodiment of the process of the present invention, three inorganic elements, two of which are radioactive, are employed. It is desirable to maintain at least 1% by weight of a radioactive polyvalent heavy metal of over 20o atomic weight in the concentrated carroting solution. The superiority of the radioactive elements is due not only to their inherent chemical nature,

ill

2 but also to the fact that the radioactivity (which is of a very mild type) appears to exert a catalytic action upon the condensation reaction of the metal proteo-mercaptides in the felting operation. it has been found that a combination of uranium, thorium and strontium gives the best results, particularly when these three elements are present in proportions to give an overall average metal atomic weight of 195 to 220, and preferably about 200. Some examples of the ratios of elements which may be employed are given in the following table, although it is to be understood that other ratios are also applicable:

Per cent U Per cent Th Per cent Sr gggg (at Wt. 238) (at Wt- 232) (8l7 Wt. 87.6) weight These elements are employed in the form of salts dissolved in nitric acid, preferably together with a small proportion of a hydrolyzing acid such as sulfuric, phosphoric or hydrochloric acids, and also preferably in presence of potassium buffering salts, such as the nitrate, sulfate, phosphate, bisulfate or bisuliite. Potassium salts are employed since they are made radioactive more readily (by presence of radioactive atoms) than buffering salts of other soluble elements.

A retarding agent is also employed to retard the energetic action of the mineral acid mixture. Such an agent may be the lower fatty acids of 1-3 carbon atoms, such as formic, acetic and propionic acids, or mixtures thereof. The corresponding halo acids, such as chloracetic, fluoropropionic, etc. may be used, provided allowance is made for the amount of halogen present (which splits ed as hydrogen halide) in the amount of hy'drolyzing acid used. It has been found that formic acid is not as strong a retarding agent as acetic acid, and hence it is generally employed whenthe fur is to be used soon. Furthermore, under the conditions existing, formic acid has a tendency to decompose, so that the solution should be used within 36 hours after it is made. 1 On the other hand, propionic acid is a stronger retarding agent than acetic acid and may be used when the fur is to be stored for some time in the wet state after carroting.

The oxidizing solution to be employed is genfur fibenwhich tend togive the fur a'yellowish color. a

In carrying out the present invention, the following solutions are first prepared:

Solution 1 4 California whites, can be worked with gravities as low as 6 B,

After dilution to proper Baum gravity, an,

7 equal volume of Solution 2 is added and the skins A 30 50% by weight of an aqueous solution :of

an inorganic acid of nitrogenlnitric or nitrous acid), or mixtures thereof isemployed, preferably of 40-48% concentration, as for example, 46%".- To this is added a small amount (0.25-0.5% by wt), say 0.35-.45%, and preferably 0.38%v :by weight, of a hydrolyzing acid, such as sulfuric,

phosphoric, or hydrochloric acid, or mixturesthereof. A 3:1 weight ratio of HC1:H2SO4 is preferred; 'There :is also;addedli.25-Q;5% :by wt. 'tpr'e'ferably 0.38%9 f a potassium tbufferingsalt, such as potassium :nitrate', and 02-05% bylwt. *of the retarding agent heretofore described.

The heavy polyvalentmetals employed in this solution are capable of reacting with :the xanthoproteic dimercaptan, and thus appear to advantageously retard'th'e condensation reaction responsible for felting. The nitrates, sulfates, chlorides or phosphates, in the propermolal ratio to give-the desired'overall average atomic weight, may 'be employed. The-acetates arei tox ic and are not too-desirable.

The gravity of this solutionis about 31.5-32" B.

Solution '2 This oxidizing solution is preferably composed of 30% aqueous hydrogenperoxide containing by wt; of hypochlorous acid (HOCl), 1% per chloric acid and 3% chloricsacid. Although'conventional oxidizing solutions have been found to give satisfactory results, Solution 2 has proved to give superior overall efiec'ts.

The procedure, .in practicing the present inven- .sian skins'require higher concentrations ll-14 B;-) depending on the season of the year when the skins are-taken. Domestic rabbits, such ,as

are treated with the resulting mixture and dried, after which :they are fibrushed, cut, and blown, and the blow-n fur is then converted into hats or cloth in the conventional manner.

The invention may be more clearly understood by reference to the following examples in which areillustratedsome of the many phases involved: 7

7 EXAMPLE I The' followingisolutions are prepared:

7 Solution A Water lbs. 35' Potassium nitrate ozs 19.7 Uranium nitrate ozs 14 Thorium nitrate ozs 6 Strontium nitrate ozs 4 Glacial: acetic -acid ;ozs;; 28 'I-I'ydrochloric acid conc.) ;oz's 28" Sulfuric-acid (c'onc.)' ozs; 8" Nitric acid (40 Be) lbs. 1015 This solution has a gravity of 32 B. .A lotof'English coney skins was treated with the above Solution A, diluted to the strength indicated, together with Solution '2 disclosed above, in-the manner heretofore outlined (i.,e.,. as disclosed in the second .and third paragraphs under Solution .2-, above. Solution A, is .a specific example ofiSolution i1 mentioned previously). 7

sodium sulfate 4 02s., hydrogen peroxide (100 vol.) lbs; sapphire blue dyeoz. Process 7 B employs, asa carroting reagent, a solution (.dilu'ted -with water to the specified gravity) of approximately the following ingredients: Chlori'c acid rl-tparts, perchloric acid 2 parts, nitric acid (40 B.:) 30 parts,:sulfuric acid 4 parts, hydrogen 7 peroxide vol.) 50 parts, and water 10 parts.

[These tests are the result of 4 pairs the mean of which are'represented by the following averages which .were taken from the same brokerage lot number 134, and selected for uniformity] 3 7 Procedures used Present invention Process F Process'iB .Cutfers lot number;

234.. .234 234. 7 Kinds of sinus used Englishaconey 2d rack; English coney Zd-rack; English coneyzd rack. Num her f SklT'S carroted per-test 200 200 200.

Strength of so]ution-- 6.l B6 I 7.0 Be; Quantity of s lution 83 ozs 85.5 ozs. Color cf-fur after drying skins NaturaL Very yellow.

Yield ofifurirom skins. Amt. fur blown on cone. Size of cone used Hardening; 2 rounds 25" x 29". 2 rounds 26" x 30" 2 rounds 2654): 30. Starting 3 rounds 21" x 27 3 rounds 23 x29 3 rounds 23% x 29". ip on setter" 1 round 19125 x 21" 2 rounds 21 x '26" 2 rounds 21 x 26%. A Machine. 15 min. 13 x18" 19 min. 13 x 19 19 min. 13 x. 19%;

Boesch ielter 5 rounds 11.5 x 17%. "B" Machine 24 min. 10% x 15%". Tensile strength from 20 determinations... 52 b 34 lbs. El ngation at break 41%.

Elastic limits 11.5%.

. 'lhisgrade of English coney. 2d rack, was somewhat better than the usual cits-0f this a e; The fur was rather :full. From the regular carroted product'the yield averaged-7 lbs. p gt races,

EXAMPLE 11 French white hair skins were next used with the reagents disclosed in Example I, but diluted to the strength indicated, employing the method heretofore outlined, and under comparable conditions with processes F and'B to give the fo-llow ing test results:

[These data-arc tn e result of 3 pairs of tests, represented by the mean as given below, which were taken from brokerage lot number 352 of French White (Bare) 1st, quality selected for uniformity] Procedures used Present invention Process IF Process B Gutters lot number 241 241. Kind of skins used-.- French white lsts French white lsts. Number of skins used.. 200 200. Strength of solution.- 8.5 Be 10.5 B. Quantity of solution. 120 ozs 134 ozs. Color of skin after dry- Slight cream Very yellow. Condition of skins... Natur Matted. Yield of fur (1-13. 9 lb. 4 oz 8 lb. 10 ozs 8 lb. 6 ozs. Weight blown. 3 Ozs 3 ozs..... 3 ozs. Size of cone 27x3l-- 27x3l" 27x3l..-.- 27"x31".

2 rounds x 29%. 2 rounds 29 x 30. 3 rounds 22 x 28.. 3 rounds 23 x 29. 2 rounds 22 x 28. 27 min. 14x19. Boesch ieltcr.. 5.5 rounds 11 x 16. B Machine 20 min. 10.5 x 15.25. Tensile strength from 16 determinations. 50.2 lbs. Elongation at break 46%. Elastic limits 11 EXAMPLE III In this case, the test run was made on Australian pelts with the reagents outlined in Example I, diluted as indicated below, and in the mann r already outlined, under comparable conditions for processes F and B, resulting in the fol lowing test results:

strontium are present in such proportion that the overall atomic weight of the three metals is about 200.

3. The process according to claim 1 in which the three polyvalent metal salts are roughly in the approximate weight proportion of uranuim 21, thorium 9 and strontium 6.

[These data are the result of 12 tests, taken from brokerage lot 619, Australian entire, selected for uniformity of fur and weight of pelts] Procedure used Present invention Process F Process B Lot number 246 246. Number of skins used 200 200.

Kind of skins used Australian entire. Australian entire. Strength of solution l0.5 Be l0.5 Be. Quantity used 123 ozs.. ozs. Color after dry Slight yellow Very yellow. Yield cut-blown 8 lbs. 2 ozs.-. 8 lbs. Size of cone x 27 x 31. Weight formcd.. 3 ozs 3 ozs. Hardening-.. 2 rounds 25 x 29. 2 rounds 25% x 29%... 2 rounds 26 x 29% Starting 3 rounds 21 x 27.. 3 rounds 22% x 28.-. 3 rounds 23 x 28%. Apron setter.. 2% round 19 x 21. A Machine 20 min. 13 x 18. Boeseh felter.. 4% rounds 11 x 16. 13" Machine 21 min. 10.5 x 15%. Tensile strength (16 tests) 37. lbs. Elon ation at break-.... 34.5%. Elastic limits 9.6%.

by the present invention ranged from 59 lb 69.5 lbs, whereas that from the conventi methods ran 39-545 lbs. Also, elongation at break for felt made according to the present invention ranged 59-68%, while those made 5. conventional reagents ranged 34.5-52%. limits for felts made according to the n invention were 19-28%, whereas the others in the range 9.6-15.4%.

We claim:

1. The process of carroting fur fibers employing a medium comprising a nitric acid solution and hydrogen peroxide, the improvement coirprising treating said fibers with said medium containing soluble salts of the two radioactive metals,

4. An improved carroting reagent comprising a medium of nitric acid, hydrogen peroxide, a soluble potassium salt, a hydrolyzing mineral acid mixture comprising hydrochloric and sulfuric acids, acetic acid and a catalytic agent consisting of soluble salts of uranium, thorium and strontium, said soluble salts being present in such proportion as to have an average atomic weight of 200.

5. An improved carroting medium according to claim 4 wherein the three metal salts are present in such proportion that the overall average atomic weight of the said metal salt is between and 220.

6. An improved carroting medium according to claim e in which the polyvalent metal salts are roughly in the weight proportion of uranium salt 7, strontium salt 2 and thorium salt 3.

'7. A carroting medium according to claim 4 containing 0.25 to 0.5% by weight of a mixed hydrolyzing agent, 0.2 to 0.5% by weight of 7 acetic 'aeid and F025 to 0:5 of a "soluble "potassifi'msalt; v

8. A' 'arioti 'ng reagent for treating fur fibers c'o m irisifig 'an aqums solution of nitric and liit'roiis' acids (EEO-50 Strength by Weight; 2-4

by Wi'ght of Soluble "salts' 'of uranium, thorium and 'trohtiinfi, said "Salts beingpreserit in such 'iprbbortions'as to have'an'average atomic weight REFERENCES CITED The following references are of record the V file of this patent:

Number Number V Y8 UNITED'STATES'PATENTS Name Date Par1s" Jan. 23, 1917 'Bohm' Apr. 23,1929 'Mercier Apr. 17,1934 Fabian -Ju1y '21, 1936 Kauffmann ....'May 11, 1937 'F'abian Jan, 17, 1939 r Page-"1.-- Jan. 26,1943 FGR-EIGN PATENTS Qountry a 1,, .1 Da Austria Feb 25, 1328 "Great Britain ;Ai1g.- 20, 1937 OTHER. REFERENCES 7 Ser, Ndfis'sabeanaakh (A.P.-C;) pub. Aprgz'z, 0 1943. r I g I 

